The present invention relates to an iron-type golf club head, more particularly to a hybrid golf club head assembled from components made of at least two kind of metal materials and a fiber reinforced resin.
Heretofore, in order to lower or adjust the position of the center of gravity and increase the moment of inertia of an iron-type golf club head, there have been widely employed a technique to insert a weight member in a lower part of the club head.
For example, in the Japanese published unexamined application No. 10-314349, as shown in FIG. 6(A), the sole (s) of the head (i) is provided with a hollow, and a weight member KO made of a tungsten alloy is placed in the hollow, and the opening of the hollow is closed by a metallic alloy plate.
In the US Patent application publication US 2007-281796-A1, as shown in FIG. 6(B), a plurality of weight members are inserted in the toe (t), heel (h) and sole (s) of the head.
In these techniques, in order to insert the weight members KO, their maximum sizes are limited, and thereby the increase in the moment of inertia and the lowering of the position of the center of gravity are limited.
Further, when making the weight members KO and forming the holes or hollows into which the weight members KO are inserted, high dimensional accuracy is required, therefore, the production efficiency is not good.